function weather_refresh_data in Weather 7

Parses raw METAR data string and stores results in database.

Parameters

string $icao: ICAO code.

object $metar: METAR data object, may be altered.

Return value

object METAR data object or FALSE.

1 call to weather_refresh_data()

weather_get_metar in ./weather.module

Fetches the latest METAR data from the database or internet.

File

./weather_parser.inc, line 35

Retrieves and parses raw METAR data and stores result in database.

Code

function weather_refresh_data($icao, &$metar) {
  $metar_raw_string = weather_retrieve_data($icao);

  // If there's new data available, parse it.
  if (!empty($metar_raw_string)) {
    $metar = weather_parse_metar($metar_raw_string);

    // Calculate the next scheduled update. Use 62 minutes after the
    // reported timestamp, to allow the data to propagate to the server.
    $next_update_on = $metar->reported_on + 62 * 60;

    // However, if the current time is more than 62 minutes
    // over the reported timestamp, do not download on every page request.
    // Therefore, we use 3, 6, 12, and 24 hours to check for updates.
    // From then on, we check once a day for updates.
    if ($next_update_on < REQUEST_TIME) {
      $last_update = $metar->reported_on;
      $hours = 3 * 60 * 60;
      while ($last_update + $hours + 120 < REQUEST_TIME) {
        if ($hours < 86400) {
          $hours = $hours * 2;
        }
        else {
          $hours = $hours + 86400;
        }
      }

      // Add 2 minutes to allow the data to propagate to the server.
      $next_update_on = $last_update + $hours + 120;
    }
    $metar->next_update_on = $next_update_on;
  }
  else {

    // The download has not been successful. Calculate the time of next update
    // according to last tries.
    if (empty($metar)) {

      // There is no entry yet, so this is the first download attempt.
      // Create a new entry with 'nodata' and give some minutes to retry.
      $metar = new stdClass();
      $metar->icao = $icao;
      $metar->reported_on = REQUEST_TIME;
      $metar->next_update_on = REQUEST_TIME + 10 * 60;
      $metar->image = 'nodata';
    }
    else {

      // There has been at least one download attempt. Increase the time of
      // next update to not download every few minutes.
      // If 24 hours are reached, we check once a day for updates.
      // This way, we gracefully handle ICAO codes which do no longer exist.
      $last_update = $metar->reported_on;
      $hours = 3 * 60 * 60;
      while ($last_update + $hours + 120 < REQUEST_TIME) {
        if ($hours < 86400) {
          $hours = $hours * 2;
        }
        else {
          $hours = $hours + 86400;
        }
      }

      // Add 2 minutes to allow the data to propagate to the server.
      $metar->next_update_on = $last_update + $hours + 120;
    }
  }

  // Wrap drupal_write_record() into try/catch block, see #1412352.
  try {

    // Make sure there's no stale data around
    db_delete('weather_metar')
      ->condition('icao', $icao)
      ->execute();
    drupal_write_record('weather_metar', $metar);
  } catch (Exception $e) {

    // Nothing to do here. If the writing fails and an exception
    // is raised, the writing of the data will happen on the next
    // update.
    watchdog_exception('weather', $e);
  }
}